Liver fibrosis is a severe medical problem, which currently doesn't have enough biological markers to accurately detect its progression. This fact is one of the greatest factors preventing the improvement of therapies available today. This book, therefore, suggests an enzyme called Heparanase, as a new biological marker for the progression and regression of liver fibrosis. In previous studies, Haparanase was shown to have a role in a wide range of normal and pathological processes, such as, angiogenesis, tumor metastasis and wound healing responses. Expressions of heparanase and key extracellular matrix (ECM) remodeling enzymes were analyzed in fibrotic rats, hepatic stellate cell (HSC) lines and heparanase over-expressing HSC lines. Heparanase activity and cell localization in activated HSCs were analyzed as well. The analyses should help shed some light on this new and exciting possible role of heparanase in liver fibrosis and recovery, and should be especially useful to students and professionals in Medical Sciences and Biology fields, or anyone else who may be interested in learning more about the biology behind liver fibrosis, or how studies are done in these fields.